305 to 350, many questions
#1
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Car: 88 Formula, 04 CTS-V, 06 Commander
Engine: 305 TBI, LS6, 4.7 V-8
Transmission: 5 spd, B&M Short Throw
305 to 350, many questions
I dont really know where to start. A year or two ago, my brother, father, and I rebuilt the 350 in his 86 Suburban. When this was done, we had the block sent to the shop and it was bored .030 with matching pistons and all other matching parts. We then put the engine back in the truck and its been running great. Couple months ago, my brother blew the tranny (which didnt owe us anything, it was origional from 86), and decided to scrap the truck. I got to thinking...
Will this Carborated 350 .030 over fit into my 88 Formula? Right now I have 305 with Throttle Body Injection, and a T-5 manual Tranny. If so, will the trottle body be able to push the 350 (with upgraded injectors)? What heads do I use? How much work am I talkin about here? Many, many more questions ... please fill me in as much as possible.
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1988 Firebird Formula 305 TBI, T-Tops, RED.
Of course ... 5-Speed
Will this Carborated 350 .030 over fit into my 88 Formula? Right now I have 305 with Throttle Body Injection, and a T-5 manual Tranny. If so, will the trottle body be able to push the 350 (with upgraded injectors)? What heads do I use? How much work am I talkin about here? Many, many more questions ... please fill me in as much as possible.
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1988 Firebird Formula 305 TBI, T-Tops, RED.
Of course ... 5-Speed
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Will this Carborated 350 .030 over fit into my 88 Formula?
Yes
Right now I have 305 with Throttle Body Injection, and a T-5 manual Tranny. If so, will the trottle body be able to push the 350 (with upgraded injectors)?
I would probably adjust the fuel pressure upward until the injectors flowed as if the were 350 injectors
What heads do I use?
Whatever is on the 350 is probably better than stock 305 TBI
How much work am I talkin about here?
Same as 86 install.
One of the things that will make or break this is the camshaft in the 350 if it is too radical then it will cause problems and require a custom chip. If you do this swap I would suggest you get a custom chip or learn how to burn your own.
If there is anything else I can do to help post it or E-mail me at hotpowerandperf@hotmail.com
HTH
John
Heart of Texas Power and Performance
#3
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Car: 1991 Camaro RS
Engine: GMPP 350 HO w/TBI
Transmission: 700R-4
Axle/Gears: 10-bolt w/3.73s
you can definitely fit the engine, thats not a problem.
depending on the specs of the motor you will probably want to get a larger throttle body or at least the larger injectors.
as far as heads go, if you want to go with aftermarket heads get the Vortec's. thay are relatively cheap, and flow really good.
you are going to need a chip for sure.
when you get a chanc, check out my web page in my signature...there is a lof of info about my 350 TBI swap. i am in the middle of adding a lot of pages, so a lot are missing so check back once in a while.
-Brian
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1991 Camaro RS - ultra blue metallic, t-tops
GMPP 350 HO crate engine - 454 TBI, MSD ignition, SLP exhaust, everything is new
700R4 - 2,400 stall converter, vette servo, shift kit
z28boy.cz28.com
Central New York F-Body Association
z28boy@twcny.rr.com AIM - "Z28 Boy"
Daily driver - <A HREF="http://members.fbody.com/z28boy/grandprix" TARGET=_blank>
1998 Pontiac Grand Prix GT</A> - 2 door, black
depending on the specs of the motor you will probably want to get a larger throttle body or at least the larger injectors.
as far as heads go, if you want to go with aftermarket heads get the Vortec's. thay are relatively cheap, and flow really good.
you are going to need a chip for sure.
when you get a chanc, check out my web page in my signature...there is a lof of info about my 350 TBI swap. i am in the middle of adding a lot of pages, so a lot are missing so check back once in a while.
-Brian
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1991 Camaro RS - ultra blue metallic, t-tops
GMPP 350 HO crate engine - 454 TBI, MSD ignition, SLP exhaust, everything is new
700R4 - 2,400 stall converter, vette servo, shift kit
z28boy.cz28.com
Central New York F-Body Association
z28boy@twcny.rr.com AIM - "Z28 Boy"
Daily driver - <A HREF="http://members.fbody.com/z28boy/grandprix" TARGET=_blank>
1998 Pontiac Grand Prix GT</A> - 2 door, black
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I am probably making this same swap soon. I had a 350 with a .512 lift cam in it. Would a cam that size be a problem?? Where can I buy a chip for it?? And how much wiring work is there in hooking the TBI back up?? Thanks.
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Car: 88 Formula, 04 CTS-V, 06 Commander
Engine: 305 TBI, LS6, 4.7 V-8
Transmission: 5 spd, B&M Short Throw
Thanks for the info so far;
The 86's 350 was done .030 stock. We had a new: main, bearings, crank, cam and everything replaced, but replaced back to stock.
So my understanding is that I would use my Intake (or maybe an upgraded one) and my throttle body with new injectors? Would it be better for me to find a TB setup in the local J-yard off of a 350?
What's a set of Vortec Heads run? 200 a piece? I would definately have a custom chip burned, theres no question about that.
How do I tell if its a one or 2 piece rear main? Any way without taking it out?
About what HP should I expect to come out of this??? Really impossible to tell in a huge Suburban.
Once again, thank you for all your info. I still dont know if this is going to happen or not, but I have the chance, so I had no choice but to look into things. If there is anything else that u know of that would give me problems, please lay them out.
KZad
------------------
1988 Firebird Formula 305 TBI, T-Tops, RED.
Of course ... 5-Speed
The 86's 350 was done .030 stock. We had a new: main, bearings, crank, cam and everything replaced, but replaced back to stock.
So my understanding is that I would use my Intake (or maybe an upgraded one) and my throttle body with new injectors? Would it be better for me to find a TB setup in the local J-yard off of a 350?
What's a set of Vortec Heads run? 200 a piece? I would definately have a custom chip burned, theres no question about that.
How do I tell if its a one or 2 piece rear main? Any way without taking it out?
About what HP should I expect to come out of this??? Really impossible to tell in a huge Suburban.
Once again, thank you for all your info. I still dont know if this is going to happen or not, but I have the chance, so I had no choice but to look into things. If there is anything else that u know of that would give me problems, please lay them out.
KZad
------------------
1988 Firebird Formula 305 TBI, T-Tops, RED.
Of course ... 5-Speed
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Car: 1991 Camaro RS
Engine: GMPP 350 HO w/TBI
Transmission: 700R-4
Axle/Gears: 10-bolt w/3.73s
this may not be right 100% of teh time depending on how you did the engine...but..is it the original block?
if it is, in '86 it was not a one piece rear main seal.
also, if it has centerbolt heads, it is a one piece seal.
but, if the heads or block are different (not stock), then these things arent good indicators.
-Brian
------------------
1991 Camaro RS - ultra blue metallic, t-tops
GMPP 350 HO crate engine - 454 TBI, MSD ignition, SLP exhaust, everything is new
700R4 - 2,400 stall converter, vette servo, shift kit
z28boy.cz28.com
Central New York F-Body Association
z28boy@twcny.rr.com AIM - "Z28 Boy"
Daily driver - <A HREF="http://members.fbody.com/z28boy/grandprix" TARGET=_blank>
1998 Pontiac Grand Prix GT</A> - 2 door, black
if it is, in '86 it was not a one piece rear main seal.
also, if it has centerbolt heads, it is a one piece seal.
but, if the heads or block are different (not stock), then these things arent good indicators.
-Brian
------------------
1991 Camaro RS - ultra blue metallic, t-tops
GMPP 350 HO crate engine - 454 TBI, MSD ignition, SLP exhaust, everything is new
700R4 - 2,400 stall converter, vette servo, shift kit
z28boy.cz28.com
Central New York F-Body Association
z28boy@twcny.rr.com AIM - "Z28 Boy"
Daily driver - <A HREF="http://members.fbody.com/z28boy/grandprix" TARGET=_blank>
1998 Pontiac Grand Prix GT</A> - 2 door, black
#7
I can't say for every block - but in my '86 bird, the 305 was indeed a 1-piece block. It's got the QJ carb, not FI. I've seen other posts that give some guidelines, but they always say "you don't know for sure unless you pull the motor"
By the way - I'm working on a similar swap. Took out the tired 305 and built a 350. biggest diff is that my motor is carbed and yours isn't.
good luck
By the way - I'm working on a similar swap. Took out the tired 305 and built a 350. biggest diff is that my motor is carbed and yours isn't.
good luck
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
<font face="Verdana, Arial" size="2">Originally posted by fazool:
I can't say for every block - but in my '86 bird, the 305 was indeed a 1-piece block. It's got the QJ carb, not FI. I've seen other posts that give some guidelines, but they always say "you don't know for sure unless you pull the motor"</font>
I can't say for every block - but in my '86 bird, the 305 was indeed a 1-piece block. It's got the QJ carb, not FI. I've seen other posts that give some guidelines, but they always say "you don't know for sure unless you pull the motor"</font>
You don't have to pull the engine: pull the inspection cover and look for the aluminum seal carrier on the back of the 1-piece rear main block (in front of the flywheel/flexplate).
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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. 2-1/2" cat-back, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 CC system w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker 2055 headers, 3" Catco cat & 3" catback, restalled TC, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).
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Car: 92 Camaro RS
Engine: 350 Crate Motor
Transmission: Tremec TKO
Axle/Gears: 10 Bolt 3.73
300 HP is easy with a 350 and TBI.350 throttle body is the same as 305, only injectors are larger.Need knock sensor & module for 350 truck motor.Ken Casey at Burt Chevrolet has part#'s you need, or you can order directly from him.(303) 761-1286 is the phone# and he's in the parts dept.
As far as cams go, you can get pretty big with the lift, but the computer can't deal with much duration and seems to like 114-116 degree lobe centers.
-Rich-
As far as cams go, you can get pretty big with the lift, but the computer can't deal with much duration and seems to like 114-116 degree lobe centers.
-Rich-
#11
Re: 305 to 350, many questions
i have a 88 camaro that had a 305 i put in a 350 motor and 350 tbi injecters i still have the 305 computer the number is 8063 what would 350 computer number be to work right with the computer harness i have in the camaro i hope i can get my rpm down 800 right now it iddles at 2200 lol
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Car: '81 Z-28
Engine: Soon to be a 383
Transmission: Muncie
Axle/Gears: 3.42
Re: 305 to 350, many questions
Try a chip from a chevy pickup with a 350... A friend of mine did that with his 91 camaro and it worked. I just don't remember if it was just the chip or the whole computer.
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